Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

5 matches
System design patterns medium

Outbox pattern reliable publish in Python with SQLite

Implements a transactional outbox with SQLite, ensuring reliable message publishing by storing events in the same DB transaction as business changes.

outbox sqlite transaction
Python
import sqlite3
from contextlib import contextmanager
from datetime import datetime, timezone


class Outbox:
    def __init__(self, db_path=":memory:"):
        self.conn = sqlite3.connect(db_path)
        self.conn.execute("""
            CREATE TABLE IF NOT EXISTS outbox (
                id INTEGER PRIMARY KEY AUTO…
11 0 Open
Streaming & messaging medium

How to Implement an Outbox Table Poll Publisher in Python

This code simulates an outbox pattern with a class that polls for pending records and publishes them as JSON messages, removing only those that are due.

outbox polling messaging
Python
import time
import json
from dataclasses import dataclass, asdict
from datetime import datetime, timedelta

@dataclass
class OutboxRecord:
    id: int
    topic: str
    payload: dict
    created_at: datetime

class OutboxPollPublisher:
    def __init__(self, poll_interval_seconds=1):
        self.poll_interval = poll…
11 0 Open
Streaming & messaging medium

Implement the Transactional Outbox Pattern with SQLite in Python

A Python implementation of the transactional outbox pattern using SQLite, ensuring atomic writes of order data and outbox events in a single transaction while supporting reliable message publishing and consumption.

outbox-pattern sqlite transactions
Python
import sqlite3
from dataclasses import dataclass
from datetime import datetime, timezone
import json

@dataclass
class Order:
    order_id: str
    amount: float
    status: str

class TransactionalOutbox:
    def __init__(self, db_path=":memory:"):
        self.conn = sqlite3.connect(db_path)
        self._create_tab…
17 0 Open
Reliability & rate limiting medium

How to Simulate an Outbox Pattern with Reliable Retry in Python

This code implements a mock outbox pattern with records, delivery attempts, and retries to simulate reliable message publishing.

outbox retry messaging
Python
import time
import itertools

class Outbox:
    def __init__(self):
        self._records = []
        self._seq = itertools.count(1)

    def publish(self, topic, payload):
        record = {
            "id": next(self._seq),
            "topic": topic,
            "payload": payload,
            "status": "pending"…
14 0 Open
Microservices patterns easy

How to Implement an Outbox Pattern Mock in Python

This code demonstrates a simple in-memory outbox pattern mock for publishing domain events and tracking pending events until they are marked as published.

outbox domain-events microservices
Python
from dataclasses import dataclass, field
from datetime import datetime
from uuid import uuid4


@dataclass
class DomainEvent:
    event_id: str = field(default_factory=lambda: str(uuid4()))
    occurred_at: datetime = field(default_factory=datetime.utcnow)


class Outbox:
    def __init__(self):
        self._events =…
13 0 Open

Browse by section

Each section groups closely related Python snippets.

Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.